Evaluation of the Sigmoid Sinus Morphology by Cone Beam Computed Tomography; Touchstone of the Posterior Cranial Fossa

Abstract

OBJECTIVEIn this study, we aimed to analyze the relationship of sigmoid sinus (SS) with external auditory canal, facial nerve and mastoid cells from an anatomical point of view, to define the position of sigmoid sinus during transmastoid, translabyrinthine, retrosigmoid (lateral suboccipital) approaches, in tympanomastoidectomy and posterior cranial fossa surgery. METHODSIn this study, the morphological structures associated with the sigmoid sinus were evaluated in cone beam computed tomography images taken between 2015-2022 years. The images of 68 males and 106 females, aged 18-65 years, obtained from the archive of xxx University Faculty of Dentistry, Department of Oral and Maxillofacial Radiology were analysed. RESULTSThe most common sigmoid sinus pattern was type II with a rate of 60.8% (n=209); the second was type III with 20.6% (n=71); and the least common was type I with 18.6% (n=64). While the distance between the horizontal line passing through the external auditory canal and facial nerve and the anterior contour of the sigmoid sinus was highest in type I (right 7.26±1.62, left 7.44±.97), it was lowest in type III (right 4, 40±1.50, left 4.84±1.16) (p<0.05). CONCLUSIONThis study hihglights the importance of the sigmoid sinus position in surgeries, with special reference to otological, neurotological and posterior cranial fossa surgeries. In order to avoid intraoperative complications, each patient should be evaluated preoperatively by appropriate radiological methods.